Tubing strings are installed into wellbores and provide for conduction therethrough of wellbore treatment fluids and/or produced fluids. Fluids flow into and out of the tubing string via fluid ports through the tubing string wall.
In one previous method, the tubing string includes sliding sleeve valves that are moveable to close and open the fluid ports. Using such tubing strings, the well can be accessed selectively through the fluid ports. For example, once the string is installed, the sliding sleeve valves can be opened for one or more fluid ports. The segments of the well accessed through the opened ports can be isolated and one or more segments may be individually treated so that concentrated and controlled fluid treatment can be provided along the wellbore by injecting the wellbore stimulation fluids from the tubing string through the opened fluid port or ports in the segment and into contact with the formation. After wellbore fluid treatment, the stimulation fluids are sometimes allowed to back flow from the formation into the wellbore tubing string. Thereafter, fluids are produced from the formation. In some embodiments, the produced fluids also enter the tubing string for flow to the surface. Examples of such wellbore treatment systems are described in U.S. Pat. Nos. 7,748,460 and 7,543,634 and PCT application PCT/CA2009/000599.
It may be advantageous in certain circumstances to locate and isolate the opened fluid ports.